Holder for shaping, slotting, and similar tools



A. C. 4TWIGG.

HOLDER FOR SHAPING, SLOTTING, AND SIMILAR TOOLS.

APPLICATION FILED ns. 26, |920.

1,355,930. Patented oet. 19,1920.

2 SHEETS-SHEET l.

A. C. TWIGG.

HOLDER FOR SHARING, SLOTTING, AND SIMILAR TOOLS.

APPLICATION, FILED EEB. 26. 1920.

2 SHEETS-'SHEET 2.

1,355,930. mma ot.'19,1920.'

UNITED sTA'riLsA PATENT `OFFICEV.

ARTHUR o. TWIGG, or BIRMINGHAM, ENGLAND.

HOLDER FOR SHAPING, SLOTTING, AND SIMILAR TOOLS.

Application filed February 26, 1920.

as shown and described in British Patent Y No. 122,981, granted to me May 25,' 1918, so as to enable such tool-making and die-cutting operationsas internal and external ,slotting and shaping to be'performed with a press-actuated tool instead of byfthe more usual method of hand-chipping with a hainmer. use in connection with any shaping, slotting or similar machine in which the head lorv slide has a reciprocating action. p

The improved holder embodies a tool housing which is capable of a 'compound movement relative to the part that is finedA to the reciprocating head or slide of the press or other actuating machine, and kis iniuenced by two sets of springs in aV manner wherein the tool c is carried; this housing which provides an effective double-reliefaction, whereby, during the return stroke of the machine, the cutting end of the tool is held in spring or yielding contact with the face of the work, thus reducing drag or fric-V tion on the tool, preserving the cutting-edge,

and preventing tool bieakages such as arev likely to occur where the tool is rigidly held in relation to the reciprocating part. Further, at the commencement of each cutting g stroke (during which a positiveA drive isV imparted to the tool) the tool is automatically but positively locked at the approprie' ate' cutting angle, but is disengaged, alsoV automatically, from the locking device whenl the positive driving effort isremoved-on the point or edge of the tool being withdrawn at the commencement of the return stroke, so as to allow the spring relief action to become and remain operativeuntill the tool' has cleared the work at the end of the return stroke, whereupon the tool becomes again locked in the cutting position before the next cut is started.

Another feature of the improved holder is that it admits of an ample range of angu- Specication of Letters Patent.

The holder is, however, adaptedfor i Serial No. 361,480.

lar adjustment or setting of the tool for altering the olea-rance or cutting angle to an inclination from the vertical suitable to the nature of the work to be performed, which enables, for instance, the tool to be set in a more upright position when slotting or internal shaping operations have to be performed on narrow or restricted surfaces, or

`in confined positions.

Figure l of the accompanying drawings shows an elevation of a form of the improved tool holder adapted for attachment to the vertically-reciprocating head or slide.

of a hand press. This view shows the tool locked at the selected angle for making itsV cutting stroke. Y

Fig. 2 is an underside plan of Fig. l.

Fig. 3 is a sectional elevation showing the j dispositionsof the two sets of controlling springs of the relief action.

Patented oct. 19, 1920.

Fign'l is \a vertical section of Fig. lupon -l the dotted line V0a.

The same-letters of reference indicate corresponding parts in the several figures.

.As will be seen fromV these drawings, the

being mounted between apair of rigid sidecheeks a3, a4, on the.V front of the bracket so` as tofbe capable of a limited compound movement therein when the relief action is operative. That is to say, the housing is provided with horizontal `journals or trunnions b', which have their bearing in apair Y of'slides d, d2, that are carried in rectangulari'slots ai", a6, in the cheeks of therbra'cket so that'the housing and' tool (when the lattool-holder comprises two main parts, viz., a

ter isv disengaged from its locking device) ,i

" are angularly displaceable on the journal beariiigsvrelatively toy thebracket, and are also vertically displaceable with the slidesy d', cl2, to an extent limited by the depth of the slots a5, a".

The housing is influenced by two sets of i:

springs e, f. The back spring eV is intertom part of the housing and eXerts an outwardthrust on the latter,at apoint below.

`'posed between the bracket andthe yrearboti ofthe gruesa', a2, and the cheeks'of'the bracket and apply a verticalupward thrust through the slides to the said housing which tends to maintain the slides against the upper ends of the slots a5, a, during the cuttinfr stroke,

he tool o which is capable of a vertical adjustment in the'housing and is locked by suitable clamping devices (such as the screws g) has its head extending above the housing; its upper extremity being formedv with a tooth or spur c which, at'theV commencement of and during each cuttingstroke, is automatically. engagedr with one or other of the notches h that are cut in the under edge'of the overhanging driver por'- `tion a7 ofthe bracket and is thereby positively locked at the proper cutting angle. When so engaged the thrust exerted by the bracket against the head of the tool Ygives a direct solid drive during' the cutting stroke.

A series of these notches 7L. are provided to admit of the inclinationof the tool from the verticalv being altered V(by turning the housing on its ljournal bearings) for varying the clearance angle or cutting angle of the same according to requirements, or to the nature of the work which thetool has to perform; it being understood that, in this setting operation, after the tool has been ad- *justed to the desired inclination by pivoting thehousing, it is slid upward in the housing so` as to take the head-spur of the same into driving engagement with thevparticular locking notch l1, that corresponds to theV Yangular setting of the tool, and then the saidtool is lixed in the housing by tightening up the clamping screws. VThus, when adjusted to the vmaximum inclination, the spur-'head of thetool Vis engaged with the innermost notch as shown in Figs. l and 3,

"locked at the said angle by the engage-V whereas when adjusted to a more upright Vor vertical position, as for working in confined areas, the tool head would be engagedV with one or other of outward notches. Inall such adjustments, the head of the tool is heldu action is operative) by the upward thrust the maximum inclination from the vertical, the positions of the arts prior to the commencement of a cutting stroke are as shown in the drawings, where the tool is positively ment of the spur head with the innermost notch of the bracket-overhang a7. the cutting stroke, the positive or rigid drive and locked in its engagement with ,Y Y the se ected notch (except when the relief During is transmitted from the driver overhang of the bracket directly onto the head of the tool, but when the cut is completed and the head of the machine commences its return stroke, the resistance set up by the drag on the tool momentarily retards the return of the slides and housing, or brings about a` centerof the ournal bearingunder thefcontrol of the back springe, vso that the tool edge is yieldingly held against the face of the work during the whole of the returny stroke, with the consequence that dead or excessive drag or friction is avoided, the cutting edge is preserved, and the risk of breakages is reduced to a minimum. Y l

Immediately the edge of fthe tool clears the work at the end of the return stroke, the

resistance which restrains the bottom springl is relieved, and the said springs expand to lift the slides and restore the head-spur'of l and tool are then free to move aboutl the the tool into driving engagement with itsnotch rin the bracket-overhang', thus correctly and positively re-locking the said tOOl yat the correct angle readyk for the next cuttin stroke.

aving described my invention,what I claim and desire to secure by Letters Pat-Y ent is s 1. A double relief-action tool-holder, comprising a bracket fixture for attachment to the reciprocating slideof the actuating machine, a tool housing journaled to slides in the bracket, a relief-action spring acting von the back' of the housing below its journal center, and relief-action springs exerting a lifting thrust against the housing slides.

2. A double relief-action tool-holder, comthe reciprocating slide ofthe actuating mathe bracket, atool carried b said housing y prising'a bracket iixture for attachment Ato. n

and having la head, 'a relie' -action spring journal center, relief-action springs exert- 'acting on the back of the housing below its ing a lifting thrust against the housing slides, and a driver-overhang on the bracket 1 formed rwith notches adapted to4 be engaged q by the head ofthe tool prior to and during the cutting stroke, and fromwhich the tool-A head is automatically disengaged at the com-- mencement of the return stroke, substantially as herein described.v

Signed at Birmingham, England, this 6th l day of February A.' D. 1920, Y

' A. c. rwiee.- 

